http://dr.lib.sjp.ac.lk/handle/123456789/10540 2026-01-07T04:02:15Z 2026-01-07T04:02:15Z Fernando, G.M.T.S. http://dr.lib.sjp.ac.lk/handle/123456789/10600 2022-03-15T06:12:12Z 2018-01-01T00:00:00Z

Identification of Urban Heat Islands &Its Relationship withVegetation Cover: A Case Study of Colombo & Gampaha Districts in Sri Lanka Fernando, G.M.T.S. Global Warming is a major environmental problem that all kind of organisms has been affected at present. Urban Heat Island (UHI) is one of primary impacts of Global Warming. UHI is a phenomenon that the temperature of urban area is higher than surrounding rural areas or suburban areas. This increasing trend of temperature in urban areas affects many environmental entities such as air quality, water resources, habitats behaviors and climate changes. The most remarkable incident that relate with UHI is the difference of thermal properties of the surfaces. Many countries experience the consequences of Urban Heat Islands in many aspects such as economic, health, social and environmental affects. Thus to mitigate such impacts of UHI, it is very important to identify the main reasons behind this. In this paper UHIs in Colombo, Gampaha Districts and the relationship between UHI and vegetation cover were analyzed based on Landsat 8, 30m resolution data. Land Surface Temperature was derived from Landsat thermal Infrared band through several equations of United State Geological Survay (USGS) guidelines using Arc GIS 10. Conversion of Digital Number (DN) values to Top of Atmosphere (TOA) Radiance, Conversion of TOA Radiance to Satellite Brightness temperature and final calculation of Land Surface Temperature considering land surface emissivity are the steps that had been done for the analysis. Vegetation cover was derived by using vegetation index with the Red and Near Infra Red bands. The result shows that the land high surface temperature directly relates with the urbanized regions where vegetation cover is very less. High temperature difference could be identified that cause to arise the urban heat island effects in Colombo & Gampaha districts. There is a strong linearly negative correlation with correlation coefficient value of -0.742 between land surface temperature and vegetation cover. 78.8 km2 (including water) of total area had been identified as NDVI value less than 0.1. And extent of high temperature area was 74.12 km2 where temperature more than 27oC at 10.22am. The area in temperature range of 25-27 was 464.95km2 and area in NDVI value range 0.1-0.2 was 333.04 km2. 1471.1 km2 was identified as NDVI value between 0.3-0.4 and the area at low temperature was 1529 km2where temperature less than 25oC. According to this results, high temperature at non-vegetated areas and low temperature at vegetated areas could be noted very clearly. This is probably due to the ecological function of vegetation that lay down the surface temperature from high evapotranspiration. Vegetated areas are mostly sensed with surface temperature.Thus research output can be useful for policy-makers and planners of development projects such as Western province Megapolis project as well as for general public to understand the urban heat island effects and importance of vegetation cover to mitigate such impacts.

2018-01-01T00:00:00Z Wakawa, L.D. Ogana, F.N. Adeniy, T.E. http://dr.lib.sjp.ac.lk/handle/123456789/10599 2022-03-15T05:52:30Z 2018-01-01T00:00:00Z

State of a Lowland Tropical Forest in South-West Nigeria Wakawa, L.D.; Ogana, F.N.; Adeniy, T.E. Forests play a significant role in human existence and survival. Timely and reliable information on the status of a forest is essential for assessing the extent of regeneration and degradation. However, when such information is lacking effective forest management practices becomes impossible. Therefore, this study assessed the tree species diversity, richness and structure of Oluwa forest reserve with the view of ascertaining it present state which is crucial for management and conservation purposes. To achieved these, a systematic line transect was used in the laying of eight (8) temporary sample plots (TSPs) of size 50m x 50m. Trees with Dbh≥10cm in the selected plots were enumerated, identified and measured. The results indicate that 535 individual trees were enumerated cutting across 26 families and 58 species. The reserve has the Margalef's index of species richness, Shannon-Weiner diversity Index (H') and Pielou's Species Evenness Index (EH) of 9.07, 3.43 and 0.84 respectively. The forest has a mean Dbh (cm), mean height (m), total basal area/ha (m2) and total volume/ha (m3) of 24.7, 16.9, 36.63 and 602.09 respectively. Majority of trees were found in the smaller diameter and height classes; giving rise to reverse J-shaped structure. The structure of Oluwa forest reserve has been altered significantly while the species diversity and richness seems to indicate a sign of improvement compared to previous studies. With proper management, the remaining fragmented forests could regenerate and replenish to save some of the original species composition of the reserve.

2018-01-01T00:00:00Z Olaniyi, O.E. Ogunjemite, B.G. Akindele, O.S. http://dr.lib.sjp.ac.lk/handle/123456789/10598 2022-03-15T04:52:32Z 2018-01-01T00:00:00Z

Degree and Determinants of Host Communities’ Socio-Economic Dependence on Forest Products of Pendjari National Park, Benin Republic: Automatic Linear Modelling Technique Olaniyi, O.E.; Ogunjemite, B.G.; Akindele, O.S. The study aimed at determining the degree and determinants of host communities’ socio-economic dependence on forest products of Pendjari National Park, Benin. Four hundred households in fourteen host communities of the Park were subjected to direct household survey through multistage sampling technique. Forest Dependency Indices were computed to determine the households’ dependence on forest products. An automatic linear modelling algorithm through forward stepwise model selection method was employed to model the main determinants to host communities' socio-economic dependence on forest products. Household age category (5-14 and above 60 years), total monthly income, education level of the household members (junior/senior high school, bachelor’s degree), place of birth, and religion were the main determinants. Most host communities were observed to be dependent on the park in varied forms and degrees, while Tanguieta and Sangou had the least and highest degree of dependence, respectively. Thus, the findings had provided a template for relevant authorities to rightly allocate resources for alternative livelihood means to the ranked host communities. However, a monitoring indicator had been developed to quantify and safeguard the harms of indigenous people to the biodiversity base. This is believed to create a synergy between sustainable development and indigenous peoples.

2018-01-01T00:00:00Z Islam, S.M.Z. Chowdhury, M.A.M. Misbahuzzaman, K. http://dr.lib.sjp.ac.lk/handle/123456789/10597 2022-03-15T04:44:45Z 2018-01-01T00:00:00Z

Models for Measuring Height-Diameter Relationships for Agarwood (AquilariamalaccensisLamk) Plantations in Bangladesh Islam, S.M.Z.; Chowdhury, M.A.M.; Misbahuzzaman, K. The relationship between tree height and diameter is an important element in growth and yield models, in carbon stock estimation and timber volume models, and in the description of stand dynamics.In this paper considered18 functional models and evaluated the performance that predict total tree height from diameter at breast height of agarwood. The models were applied to A.malaccensisLamk (Agarwood) which is economically important tree species planted in some potential forest areas of Bangladesh.A total of 5,866 tree heights and corresponding diameters at breast heights were extracted from many forest areas in Sylhet, Chittagong, Cox's Bazar and Chittagong Hill Tracts (Rangamati) forest division. The model goodness of fit values were evaluated in terms of adjusted coefficient of determination (R2), root mean squared error (RMSE), Akaike’s information criterion (AIC),Durbin- Watson statistic value,homogeneity of the residuals and significance of the regression parameters. The results of the study indicated that the height-diameter relationship can best be described by non-linear models. The best three models selected for the species with ranking in terms of goodness of fit. The Gompertz𝐻 = 17.0360 × exp⁡(−2.3614 × exp(−0.1009 × 𝐷)); Parabolic𝐻 = 0.4561 + 0.7735 × 𝐷 − 0.0089 × 𝐷2and Logistic (1 6.1156 ) 15.2424 0.1674 D e H      with R2=0.91 were height-diameter models performed better than other models.

2018-01-01T00:00:00Z